Beverage bottle case



April 21,1964 c. c. WORMER m 3,129,838

BEVERAGE BOTTLE CASE Filed April 6, 1961 4 Sheets-Sheet 2 INV EN TOR.

CLARK C Moe/mm, E y

I I, I I, I I I April 1954 d. c. WORMER m V 3,129,838

BEVERAGE BOTTLE CASE Filed April 6, 1961 4 Sheets-Sheet 3 fl fi 6 INVENTOR.

CLARK a Wok/15R, ID. BY

W/Lso/v, SETTLE a CRAIG -/4TTORNEY5 P 1964 c. c. WORMER m 3,129,838

BEVERAGE BOTTLE CASE Filed April 6, 1961 4 Sheets-Sheet 4 INV EN TOR.

CLHRK c. MIRMER, 12! BY MLSON, SETTLE & CR/J/G ,4T70RNEKS' United States Patent 3,129,838 BEVERAGE BOTTLE CASE Clark C. Worrner III, 25389 Meridian, Grosse Ile, Mich. Filed Apr. 6, 1961, Ser. No. 101,159 2 Claims. (Cl. 22021) This invention relates to a beverage bottle case, and more particularly to an improved beverage bottle case of slush molded, fiber-reinforced synthetic resin.

Beverage bottle cases of the 24 bottle variety have heretofore been largely fabricated from wood of about /2 inch thickness for sufiicient structural strength. Frequently the wood in the ends of the cases is approximately twice the thickness of the wood in the sides. The inner dimensions of the case are determined by the size and number of the bottles to be held. The exterior dimensions necessarily result from these interior dimensions and the thickness of the Wood in the sides and ends. The exterior dimensions have become a standard for positioning means on machinery which packs filled bottles into the cases. These prior cases have been provided with suitable bottle separators; and at the corners and along the bottom they are also provided with steel reinforcing strips for adequate burst strength. These prior cases have been rather costly items, requiring seasoned wood, which must be carefully cut to proper dimension and then assembled by semi-hand methods. Also extra work is required for manually applying the aforementioned reinforcement strips. Additionally since the cases are of wood, they are heavy, particularly when filled with full bottles, and provide difiicult handling for a delivery man.

It has been the custom to package bottles, for example six, in small cardboard cartons and to pack four of such cartons into a case. Because the corners of the cartons and the interior corners of the wooden cases are both necessarily square, this has caused difficulty in placing the square cartons in the cases or removing them from the cases without tearing or crushing the corners of the cartons.

Further, since the steel reinforcement strips on the bottoms of the cases become abraded and roughened in use, they scratch the caps of bottles upon which they are stacked, as in palletizing and truck handling. Thus consumer resistance is often encountered because the scratched caps convey an impression to the customer that the merchandise is old or imperfect.

Wood cases of the prior art also suffer the disadvantages that they are subject to deterioration by moisture, weather, etc. and are of comparatively short life.

Accordingly a step forward in the art of beverage handling would be provided by the creation of light weight, durable and easily manufactured bottle cases for the transport, delivery and handling of bottle beverages. This step forward in the art of beverage bottle cases would also be enhanced by providing an improved beverage bottle case which is resistant to deterioration as by moisture, steam cleaning and the like; which is light in weight, yet tough and strong to withstand vigorous handling and which is of such a degree of resiliency to permit palletizing or stacking of cases of filled beverage bottles without marring the caps of the filled bottles. Still further, this step forward in the art of beverage bottle cases would be substantially enhanced by providing an improved beverage bottle case which is adapted to use with existing packaging machinery adapted to packaging beverage bottles in conventional wood beverage bottle cases.

It is therefore an important object of the present invention to provide an improved beverage bottle case.

Another object is to provide an improved beverage bottle case of reinforced synthetic resin and adapted to use with existing wood case filling equipment.

A further object is to provide an improved beverage bottle case which is of simple and economical manufacture on a production basis, substantially without hand labor.

A still further object is to provide a reinforced synthetic resin, slush molded beverage bottle case of improved durability to moisture, weathering and the like.

Another object is to provide an improved beverage bottle case of thin molded plastic material in which the inside bottle supporting surfaces and the outside exterior dimensions of the case are sufiiciently close to those in existing wooden cases that the improved case embodying this invention can be handled interchangeably on existing machinery designed to fill wood cases with bottles.

Another object is to provide a molded case of the character described in which the interior vertical corners of the case are formed as cylinders projecting outside of the intersection of the planes of the inner vertical supporting surfaces, so that when a case is packed with cartons of bottles the cartons are supported with their corners out of contact with the inside corners of the case.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

In the drawings:

FIGURE 1 is a plan view of a beverage bottle case made in accordance With the present invention;

FIGURE 2 is a vertical section view taken along line 22 of FIGURE 1;

FIGURE 3 is a partial end elevation View taken along line 3-3 of FIGURE 2;

FIGURE 4 is an enlarged fragmentary plan view of a case of the present invention;

FIGURE 5 is an enlarged fragmentary plan view il-- lustrating the manner in which a thin separator eleme nt is secured in position by the retaining ridges formed on the side walls of the case;

FIGURE 6 is an enlarged fragmentary plan view similar to FIGURE 5 illustrating the manner in which a thick separator element is secured in position by the retaining ridges formed on the side walls;

FIGURE 7 is an enlarged partial sectional view taken along line 77 of FIGURE 1;

FJGURE 8 is an enlarged partial plan vie-w showing the manner in which six-pack cartons can be carried by the case structure of the present invention;

FIGURE 9 is a partial side elevational view of an improved 24 bottle divider insert adapted for use in the case illustrated in FIGURES 1-8; and

FIGURE 10 is an enlarged fragmentary sectional view illustrating the manner in which the upper end portions of the center divider are formed to provide smooth hand grips at the ends of the case.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Briefly the present invention relates to an improved case for transporting glass beverage bottles for delivery of beverage products to consumers and for return of the empty bottles to the bottling plant for cleaning, refilling and repetition of the manufacturing and marketing cycle. In accordance with the present invention, a novel beverage bottle case has been provided which is of unitary con- 3 struction and is made of slush-molded reinforced synthetic resin to provide reduced manufacturing costs and at the same time providing a product of improved appearance and durability. The improved case of this invention is versatile in that it is adapted to the transport of individual bottles, or bottles prepackaged for example in six-pack cardboard cartons, and it is also versatile in that it is adapted for use with packaging equipment used for filling wood cases of the prior art.

As shown in FIGURE 1, the improved beverage bottle case of the present invention includes a base 12, with upstanding sidewalls 14 and upstanding end Walls 16 extending substantially vertically from the periphery of the base and formed integrally therewith. The side walls 14 and end walls 16 are joined integrally at their ends to form corners 18.

As previously mentioned, the cases 10 of the present invention are adapted to use with existing equipment designed for packaging beverage bottles in Wood cases. However, since the reinforced resin from which cases of the present invention are made is much stronger than wood per unit thickness, the bottom 12 and side and end walls 14 and 16 need not be made to full wood thickness to provide strength comparable to wood. Accordingly, the bottom 12 and side and end walls 14 and 16 are made much thinner than wood with resultant saving in materials to provide a lighter yet correspondingly strong unit. However, both inside or bottle supporting surfaces and exterior dimensions are placed at the same limits as corresponding surfaces of wood cases to provide for packaging and handling with existing equipment designed for use with wood cases. Thus the present invention provides an improved beverage bottle case which can be used with existing packaging machinery and thus any necessity of expenditure for either modification or replacement of existing packaging machinery is avoided.

Due to the high strength of the reinforced synthetic resin utilized, the base 12 is only about inch thick as compared to the approximate /2 inch thickness of wood cases. However, in order to provide loading limits corrmponding to those of wood cases, the base is provided with 24 sets 20 of bottle supports 22. Each set 20 includes three bottle supports 22 and each support comprises an upstanding projection of about inch height and formed integrally with the base 12. The bottle supports 22 are of elongated configuration of about /2 inch in length and are provided with flat and planar aligned upper support surfaces 24 for the cooperative support of the base of a beverage bottle thereon. This is illustrated in FIGURES 4 and 7.

The bottle supports 22 of a set 20 are spaced at 120 with respect to each other within a circle defined approximately by the perimeter of the base of a beverage bottle, as best shown in enlarged FIGURE 4. Therefore the three supports of a set cooperate to provide a bottle supporting platform raised about A of an inch above the upper surface of the base 12, see FIGURE 7.

A clearance space 26 is thus provided beneath the bottles 28, FIGURE 7, and this aids in keeping the bottoms of the bottles clean and elevated above any fluid or solid debris which might fall to and collect in the bottom of the case, as for example when a bottle might be broken to spill its fluid contents and glass fragments into the bottom of the case. Thus the present construction provides an improvement in keeping newly filled beverage bottles clean for delivery to their consumer destination.

It is to be considered within the scope of the invention to provide drain holes in the bottom of the case, particularly at the end, to permit fluids to drain out, as when the cases are canted at a 10 to 12 degree angle from horizontal as on a delivery truck. This angle of loading is utilized to prevent the cases from falling off the truck on turns, but causes fluids to drain to the ends ofthe case to more than fill the space 26 and thus soil bottles. Ac cordingly, drain holes would overcome this problem.

As best shown in FIGURES 2, 5 and 6, the side walls 14 and the end walls 16 of the case 10 are provided with pairs of parallel and integrally formed elongated separator support ridges 30. The separator support ridges 30, have outwardly converging side walls 32 whereby they define inwardly converging slots 34. These inwardly converging slots 34 are adapted to snugly engage the ends of bottle separators 36 and 38 and because of the inwardly converging nature of the slots they are adapted to retain bottle separators of varying thickness in fixed position by frictional engagement. This is illustrated in FIGURES 5 and 6, FIGURE 5 showing the end of a thin separator resting at the bottom of the converging slot 34 and FIGURE 6 showing a thicker separator engaged with the converging slot about half way up the slanting side walls 32.

As shown in FIGURES 1 and 2 the side walls 14 are provided with five sets of separator support ridges 30, providing for the receipt of five cross separators 36, which with the end walls provide a case six bottle compartments long. The end walls 16 are provided with three sets of separator support ridges 30, for the receipt of three longitudinal separators 38, FIGURE 8, and with the side Walls 14 provide a case four bottle compartments wide, thus by the use of appropriate separators the case can be divided into 24 separate compartments. The separators are suitably notched to provide for crossing each other, as is Well known in the art, and accordingly illustration of this feature is omitted to avoid unnecessary lengthening of the present specification.

Inasmuch as the separator support ridges define in- Wardly converging slots 34, they are adapted to restrainingly engage the ends of separators 36 in removable relationship, thereby permitting flexibility of arrangement of separators. As shown in FIGURE 8, a lateral separator 36 is positioned between the middle pairs of side wall support ridges 38 and a longitudinal separator 38 is positioned between the middle pairs of end wall support ridges, thus dividing the case 10 into four compartments 2 bottles wide and three bottles long. In this arrangement the compartments are adapted to receive sixpacks or cardboard cartons containing six bottles each.

As will readily be seen, any other arrangement of the compartments can be established for the receipt of other packs by appropriately positioning the separators 36 and 38; thus by the use of two equally spaced separators extended between the second and fourth sets of separator support ridges 30 of the side walls 14 and a single separator between the middle set of separator support ridges 39 on the end wall 16, the case can be divided into six compartments, each four bottles square as shown in FIG- URE 4. This would provide an arrangement for six fourpacks.

In still another arrangement, a single separator can be extended between the center sets of separator support ridges 39 on the end Walls 16. This will be effective to divide the case into two compartments which are six bottles long and two bottles Wide. Thus, if desired, two 12-packs can be accommodated.

As previously mentioned, and as shown in FIGURES 1, 4 and 7, the side walls 14 and the end walls 16 are joined integrally at their ends to form corners 18. Since the present invention is intended to preserve the exterior dimensions of wood cases, it will be noted that the corners are formed as cylinders 40 which project beyond the end walls 16. The outside of the cylinder projects from the end wall approximately the same distance as the flange 48 referred to below. The cylinder 40 is of relatively small radius so that it provides a sufficiently sharp corner to engage conventional positioning means in the case handling and filling equipment. As shown in FIGURES 4 and 8, in dotted outline, the corner thickness at the radial relief may be slightly greater than the thickness of either the side wall 14 or the end wall 16 and the exterior 42 of the radially relieved portion 40 is thereby strengthened and brought out to wood case exterior dimension.

The greater thickness of the radial portion as at 42 provides additional strength to the case against bumping and handling and possible breakage at these critical contact points.

An advantage provided by the radially relieved or cylindrical portions 40 is illustrated in FIGURE 8 wherein a six-pack is illustrated. It will be noted that the separator support ridges 30 extend out a short distance from the inner surface of the side walls 14 and form supporting surfaces for the walls of the cartons, and so space the six-pack a short distance away from the side wall. Similarly the separator support ridges 30 on the end wall 16 space the six-pack a short distance away from the end wall 16. Since the corners 18 are relieved by being formed into cylinders 40, the inner surface of the corner is outwardly displaced from the intersection of the planes of the inner tips of the separator supporting ridges 32 on both the end walls and side walls so that the corresponding corner of this six-pack is accordingly kept out of contact with the inside corner of the case and damage or crumpling of the cardboard from which the six-pack is made is thereby avoided.

Thus the radially relieved portion has a three-fold effect; because of its thicker section it provides wood case dimension and additional strength to the case at critical areas thereof and because of its relieved nature it provides a clearance preventing damage to prepackaged cases carried thereby.

As previously mentioned, the sidewalls 14 of the case of the invention are made very thin due to the strength of the fiber reinforced resin. In order to bring the exterior dimension out to the exterior dimension of conventional wood cases, a flange 44 is formed along the upper edges of each of the side Walls 14. These flanges 44 are of rectangular section with their outer surfaces 46 at the same lateral dimension as a wood case. Thus the flange 44 not only serves to bring the side wall dimensions out to that of a wood case, but it also stiifens the side wall, which due to its thin section is somewhat flexible, despite its high strength. Therefore, a good rigid construction is provided.

Also, formed integrally with the flange 44 which extends along the upper surfaces of the side walls 14, there is provided a flange 48, formed along the upper edges of each of the end walls 16. The flange 48 is of inverted L-shaped configuration as shown in FIGURES 2 and 7, and includes a horizontally disposed body 50 and a downwardly extending vertically disposed arm 52 spaced a short distance from the outer surface of the end wall 16. Ribs 54 are formed at intervals beneath flanges 48 for stiffening support.

As shown in dotted outline in FIGURES 2, 4 and 8, vertically disposed spacer ribs 56 are formed integrally with the side walls 14 and extend substantially down to the base 12. These are suitably formed in section as segments of a circle, FIGURES 4 and 8, and are about inch thick at their major dimension and bring the side wall dimension out to the corresponding dimension of wood cases.

As shown in FIGURES 2 and 3, hand grips 58 are provided in the end wall 16, in cooperative relationship to end wall flanges 48 for lifting and handling the cases 10. When the case is formed, it is preferably made by a slush molding technique, to be more fully described later, and by such technique the end walls are formed solid. Accordingly, the hand grips 58 are provided by die cutting oblong openings 60 into the end walls 16, care being taken that the upper edges of said oblong openings 60 are substantially in aligned relationship with the lower edges of the arm 52 of the end wall flange 48, see the left side of FIGURE 2. This arrangement provides a substantially bar-like grip which the fingers of the hand may encircle by insertion through the opening 60.

As shown in FIGURE 3, which is a fragmentary elevational view taken along the line 3--3 of FIGURE 2, the opening 60 has its upper peripheral edge positioned slightly below the upper ends of the center set of separator support ridges 30, leaving a portion 30 of the separator support ridges above the opening 60. Thus ample support is provided for bottle separators above and below the openings 60*.

In one embodiment of the present invention a novel separator 62, as shown in FIGURES 9 and 10, is employed in a 24 bottle case arrangement. This separator 62 comprises longitudinal metal runner bars 64, extending the length of the case 10, and lateral metal runner bars 66 extending the width of the case. The bars 64 overlie the bars 66 and are joined at their intersections with the bars 66 as by spot welding, as indicated at 68. Bottle separators 70, of generally V-shaped configuration, are provided at the upper ends of their arms 72 with horizontally disposed attachment rfingers 74 which are connected to the bars 64 and 66 as by spot welding, as shown at 68. Since the separators 70 are of a length substantially equal to the diameter of a bottle and are provided (for both the longitudinal runner bars 64 and the lateral runner bars 66, it will be seen that the separator 62 is adapted to divide the case into 24 separate bottle compartments.

The novel separator 62 is suitably fabricated of steel rod stock and is plated with a suitable corrosion resistant metal such as chromium to add long life to the unit.

As shown in FIGURE 1-0, the middle longitudinal runner 64 is provided at its ends with upturned portions 76 terminating in a horizontally disposed finger 78' adapted to fit between the portions 3d of the support ridges above the opening 60 and into an aperture 82 thereby additionally locking the unit 62 into place in the beverage case 10. Also the end separator '72 has its attachment finger angled at 74' to underlie the upturned portion 76 of the center runner 64. Thus a smooth hand grip is provided without rough ends of the longitudinal runner 64 or separator '72 being exposed to scratch the finger.

As shown in FIGURE 9, the bight portions 80 of the spacers 70 are adapted to fit between the bottle supports 22 on the base 12 ofthe case 10 and thus the unit rests firmly against the base 12 with the ends of the longitudinal runners 64 and the lateral runners 66 restrainingly engaged in the inwardly converging slots 34 between the separator support ridges 30.

As previously mentioned, the spacers 70 of the separator 62 are of generally V-shaped configuration and thus the arms 72 converge downwardly to guide bottles into proper position in the case. Thus any bottle cooking or misalignment caused by the packaging machine will be compensated for by the guiding nature of the separator arms 72. Further, since these arms converge at the bottom of the case, they provide subjacent support to the base of bottles placed in the case to prevent shifting and breakage in transit and handling.

The novel separator 62 is advantageous when used in combination with the novel case 10 because in modern processing plants, the cases are inverted and steam cleaned prior to repacking with freshly filled bottles of beverage. Since the separator is fabricated of plated metal and since the case is fabricated of water resistant synthetic resin, a highly durable and sanitary combination structure is provided. This is a definite advantage over wood cases with wood separators which swell when wetted and shrink when subsequently dried. Further, since such swelling and shrinking causes cracks in the wood, bacteria of many kinds can be harbored in such cracks rendering the unit unsanitary. Since all surfaces of both the separator and case of the present invention are impervious, a highly sanitary unit is thereby provided.

Materials of Construction As previously mentioned, the improved bottle cases of the present invention are made by slush molding.- In accordance with this process, a mat of reinforcing fibers is saturated with a liquid thermosetting resin mixture to provide a wet lay-up. This wet lay-up is then placed upon a male mold and a suitable female mold is brought down over the male mold, pressing the resin and fiber mixture into intimate contact with all depressions or other configurations of both molds. Heat is then applied to cure and harden the resin and convert the lay-up into a rigid, formed part. Thereafter the part is removed from the molds and any flash is trimmed away; then the part is machined as necessary. In making the present bottle cases, the only machining or cutting necessary is the diecutting operation previously mentioned in making the hand grip opening 60, FIGURES 2 and 3.

In a preferred aspect, a polyester molding resin mixture is employed with sisal reinforcement fibers. It has been found that this combination provides a strong case, yet one which is not sufliciently hard to deform or scratch bottle caps when loaded cases are stacked for shipping and handling. In such arrangement the bottom of the case rests on the caps of the next lower case and this has caused scratching and defacement of the bottled product in the past. Thus a further improvement over prior art wood cases with their inherent scratching properties on bottle caps is provided by the present invention.

While the preferred embodiment of this invention utilizes a polyester resin with sisal fibers, it is to be included within the scope of the invention to use other liquid thermosetting resin mixtures such as phenol-formaldehydes, urea-formaldehydes, melamine-formaldehydes and the like.

Also, other reinforcement fibers can be employed, and glass fibers are to be included. These can take the form of a so-called random fiber mat which is a mat of continuous fibers in strand form laid in random array upon each other and bonded together with a temporary binder such as starch. Additionally, continuous glass fibers in the form of chopped strand can be used. Also chopped roving can be used, roving being the designation for a plurality of strands lightly bonded together in aligned relationship analogous to a cable. Usually about strands are made into a roving. When chopped, this provides a very excellent reinforcement material for thermosetting resins. When using glass fibers as a reinforcement, however, a harder and smoother finish is provided to the finished product. This harder and smoother finish gives less tooth to the surfaces of the cases and accordingly they may be somewhat more prone to slide about during stacking and handling. To avoid this tendency, the preferred combination referred to above therefore comprises a polyester resin in combination with sisal fibers; this combination provides an ideal resilience. Nevertheless, the glass fibers are to be included within the scope of the invention.

Advantage Summary Although the various advantages inherent in the construction of the present invention have been enumerated throughout the specification at appropriate points where they arose, they are summarized here to highlight the invention. Thus a unitary, slush-molded, fiber-reinforced, synthetic resin bottle case is provided which is of such configuration as to be used with existing packaging equipment for wood cases. Further, the case is light in weight,

durable and easily manufactured substantially without hand labor. Also, the case, and the novel divider, due to the impervious surfaces of these units, provide a combination structure adapted to be cleaned and thus a highly sanitary product is provided as compared to the prior art.

Having thus described my invention, I claim:

1. A unitary molded case for beverage bottles and the like comprising in combination a flat rectangular base with flat side walls and flat end walls extending substantially perpendicularly from the base, said base and walls being substantially of uniform thickness, pairs of ridges formed integrally with the walls and projecting inwardly therefrom for holding the ends of separator elements, integral projections on the inner surface of the base for supporting the bottoms of glass bottles above the base, integral flange means around the top edges of all the walls including side flanges projecting outwardly from the side walls and end flanges projecting outwardly from the end walls, the end flanges being materially thicker than the side flanges and projecting materially further from the end walls than the side flanges project from the side walls, each corner at the juncture of an end Wall and a side wall being formed as a vertical cylindrical section projecting radially beyond the end walls approximately the same distance as the end flanges, said cylindrical section having an inner surface tangential to the inner surface of the side wall and projecting outwardly beyond the inner surface of the end wall.

2. A unitary molded case for beverage bottles and the like comprising in combination a flat rectangular base with flat side walls and flat end walls extending substantially perpendicularly from the base, said base and walls being substantially of uniform thickness, pairs of ridges formed integrally with the walls and projecting inwardly therefrom for holding the ends of separator elements, integral projections on the inner surface of the base for supporting the bottoms of glass bottles above the base, integral flange means around the top edges of all the walls including side flanges projecting outwardly from the side walls and end flanges projecting outwardly from the end walls, the end flanges being materially thicker than the side flanges and projecting materially further from the end walls than the side flanges project from the side walls, each corner at the juncture of an end wall and a side wall being formed as a vertical cylindrical section the inner surface of which is tangential to the inner surface of the side wall and projects outwardly beyond the inner surface of the end wall, the outer surface of said cylindrical section projecting outwardly from the end wall to the outer edge of the end flange, said cylindrical section having a wall thickness greater than the thickness of the base and walls of said case.

References Cited in the file of this patent UNITED STATES PATENTS D. 171,132 Hulson Dec. 22, 1953 2,025,769 ODell Dec. 31, 1935 2,414,171 Schraif Jan. 14, 1947 2,667,284 Hoch Jan. 26, 1954 2,743,030 Read Apr. 24, 1956 2,781,147 Rushman Feb. 12, 1957 2,970,715 Kappel Feb. 7, 1961 FQREIGN PATENTS 767,767 Great Britain Feb. 6, 1957 

1. A UNITARY MOLDED CASE FOR BEVERAGE BOTTLES AND THE LIKE COMPRISING IN COMBINATION A FLAT RECTANGULAR BASE WITH FLAT SIDE WALLS AND FLAT END WALLS EXTENDING SUBSTANTIALLY PERPENDICULARLY FROM THE BASE, SAID BASE AND WALLS BEING SUBSTANTIALLY OF UNIFORM THICKNESS, PAIRS OF RIDGES FORMED INTEGRALLY WITH THE WALLS AND PROJECTING INWARDLY THEREFROM FOR HOLDING THE ENDS OF SEPARATOR ELEMENTS, INTEGRAL PROJECTIONS ON THE INNER SURFACE OF THE BASE FOR SUPPORTING THE BOTTOMS OF GLASS BOTTLES ABOVE THE BASE, INTEGRAL FLANGE MEANS AROUND THE TOP EDGES OF ALL THE WALLS INCLUDING SIDE FLANGES PROJECTING OUTWARDLY FROM THE SIDE WALLS AND END FLANGES PROJECTING OUTWARDLY FROM THE END WALLS, THE END FLANGES BEING MATERIALLY THICKER THAN THE SIDE FLANGES AND PROJECTING MATERIALLY FURTHER FROM THE END WALLS THAN THE SIDE FLANGES PROJECT FROM THE SIDE WALLS, EACH CORNER AT THE JUNCTURE OF AN END WALL AND A SIDE WALL BEING FORMED AS A VERTICAL CYLINDRICAL SECTION PROJECTING RADIALLY BEYOND THE END WALLS APPROXIMATELY THE SAME DISTANCE AS THE END FLANGES, SAID CYLINDRICAL SECTION HAVING AN INNER SURFACE TANGENTIAL TO THE INNER SURFACE OF THE SIDE WALL AND PROJECTING OUTWARDLY BEYOND THE INNER SURFACE OF THE END WALL. 